Re: pg_waldump and PREPARE

Thomas Munro <thomas.munro@gmail.com>

From: Thomas Munro <thomas.munro@gmail.com>
To: Julien Rouhaud <rjuju123@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Fujii Masao <masao.fujii@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-08-01T11:05:34Z
Lists: pgsql-hackers
On Thu, Jul 4, 2019 at 8:25 PM Julien Rouhaud <rjuju123@gmail.com> wrote:
> On Thu, Jul 4, 2019 at 9:45 AM Michael Paquier <michael@paquier.xyz> wrote:
> > On Wed, Jul 03, 2019 at 08:23:44PM +0200, Julien Rouhaud wrote:
> > > So the patch compiles and works as intended. I don't have much to say
> > > about it, it all looks good to me, since the concerns about xactdesc.c
> > > aren't worth the trouble.
> > >
> > > I'm not sure that I understand Michael's objection though, as
> > > xl_xact_prepare is not a new definition and AFAICS it couldn't contain
> > > the records anyway.  So I'll let him say if he has further objections
> > > or if it's ready for committer!
> >
> > This patch provides parsing information only for the header of the 2PC
> > record.  Wouldn't it be interesting to get more information from the
> > various TwoPhaseRecordOnDisk's callbacks?  We could also print much
> > more information in xact_desc_prepare().  Like the subxacts, the XID,
> > the invalidation messages and the delete-on-abort/commit rels.
>
> Most of those are already described in the COMMIT PREPARE message,
> wouldn't that be redundant?  abortrels aren't displayed anywhere
> though, so +1 for adding them.
>
> I also see that the dbid isn't displayed in any of the 2PC message,
> that'd be useful to have it directly instead of looking for it in
> other messages for the same transaction.

Hello all,

I've moved this to the next CF, and set it to "Needs review" since a
rebase was provided.

-- 
Thomas Munro
https://enterprisedb.com



Commits

  1. Fix comment in xact.h

  2. Make pg_waldump report more detail information about PREPARE TRANSACTION record.

  3. Store 2PC GID in commit/abort WAL recs for logical decoding